Chronic positive mood (CPM) has been shown to confer a wide variety of social, functional, and health benefits. Some researchers have argued that humans evolved to feel CPM, which explains why most people report better than neutral mood (the “positivity offset bias”) and why particularly happy people have particularly good outcomes. Here, we argue that the Duchenne smile evolved as an honest signal of high levels of CPM, alerting others to the psychological fitness of the smiler. Duchenne smiles are honest because they express felt positive emotion, making it difficult for unhappy people to produce them. Duchenne smiles enable happy people to signal and cooperate with one another, boosting their advantages. In our literature review, we found (a) that not all Duchenne smiles are “honest,” although producing them in the absence of positive emotion is difficult and often detectable, and (b) that the ability to produce and recognize Duchenne smiles may vary somewhat by a person’s cultural origin. In the final section of the article, we consider behavioral influences on CPM, reviewing research showing that engaging in eudaimonic activity reliably produces CPM, as posited by the eudaimonic-activity model. This research suggests that frequent Duchenne smiling may ultimately signal eudaimonic personality as well as CPM.

慢性积极情绪 (CPM) 已被证明具有广泛的社会、功能和健康益处。一些研究人员认为，人类进化到能够感受到 CPM，这解释了为什么大多数人报告的情绪比中性更好（“积极抵消偏差”），以及为什么特别快乐的人会有特别好的结果。在这里，我们认为 Duchenne 微笑演变为高 CPM 水平的诚实信号，提醒其他人注意微笑者的心理健康。Duchenne 微笑是诚实的，因为它们表达了积极的情绪，使不快乐的人很难产生这种微笑。Duchenne 微笑使快乐的人能够相互发出信号并相互合作，从而增强他们的优势。在我们的文献综述中，我们发现 (a) 并非所有杜兴微笑都是“诚实的，”虽然在没有积极情绪的情况下产生它们是困难的并且通常是可以检测到的，并且（b）产生和识别杜兴微笑的能力可能会因一个人的文化起源而有所不同。在文章的最后一部分，我们考虑了行为对 CPM 的影响，回顾了研究表明参与 eudaimonic 活动可靠地产生 CPM，正如 eudaimonic 活动模型所假设的那样。这项研究表明，频繁的 Duchenne 微笑可能最终表明 eudaimonic 个性以及 CPM。正如 eudaimonic 活动模型所假定的那样。这项研究表明，频繁的 Duchenne 微笑可能最终表明 eudaimonic 个性以及 CPM。正如 eudaimonic 活动模型所假定的那样。这项研究表明，频繁的 Duchenne 微笑可能最终表明 eudaimonic 人格和 CPM。